package com.ea.common.utils;
import java.io.Serializable;
import java.security.SecureRandom;
import java.util.Date;
import java.util.UUID;


import org.apache.shiro.session.Session;
import org.apache.shiro.session.mgt.eis.SessionIdGenerator;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Service;

/**
 * 封装各种生成唯一性ID算法的工具类.
 * @author 邢广军
 */
@Service
@Lazy(false)
public class IdGen implements  SessionIdGenerator {

	private static SecureRandom random = new SecureRandom();
	
	public static String[] chars = new String[] { "a", "b", "c", "d", "e", "f",
		"g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s",
		"t", "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4", "5",
		"6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H", "I",
		"J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",
		"W", "X", "Y", "Z" };
	
	/**
	 * 封装JDK自带的UUID, 通过Random数字生成, 中间无-分割.
	 */
	public static String uuid() {
		return UUID.randomUUID().toString().replaceAll("-", "");
	}
	
	/**
	 * 使用SecureRandom随机生成Long. 
	 */
	public static long randomLong() {
		return Math.abs(random.nextLong());
	}


	


	@Override
	public Serializable generateId(Session session) {
		return IdGen.uuid();
	}
	
	public static String randomStr() {
		StringBuffer shortBuffer = new StringBuffer();
		String uuid = UUID.randomUUID().toString().replace("-", "");
		for (int i = 0; i < 8; i++) {
			String str = uuid.substring(i * 4, i * 4 + 4);
			int x = Integer.parseInt(str, 16);
			shortBuffer.append(chars[x % 0x3E]);
		}
		return shortBuffer.toString();

	}
	
	public static String getToken(){
		StringBuffer sb = new StringBuffer();
		for(int i=0;i<3;i++){
			sb.append(randomStr());
		}
		Date date = new Date();
		sb.append(date.getTime());
		return sb.toString();
	}
	
	public static void main(String[] args) {
		System.out.println(IdGen.uuid());
		System.out.println(IdGen.uuid().length());
		
	}

}
